Page 690 of 917
ES350_300h_OM_OM33A60U_(U)
6896-3. Do-it-yourself maintenance
6
Maintenance and care
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the engine is cold.
■Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line. ( P. 821, 824)
■Power control unit coolant reservoir (hybrid vehicles)
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line. ( P. 8 2 4 )
Coolant
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690
ES350_300h_OM_OM33A60U_(U)
6-3. Do-it-yourself maintenance
■Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life
hybrid organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deionized
water. (Minimum temperature: -31 F [-35C])
Canada:
“Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% deionized
water. (Minimum temperature: -44 F [-42C])
For more details about coolant, contact your Lexus dealer.
■If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine/power control unit coolant reservoir caps,
drain cock and water pump.
If you cannot find a leak, have your Lexus dealer test the cap and check for leaks in
the cooling system.
CAUTION
■When the engine is hot
Do not remove the engine/power control un it coolant reservoir cap or the radiator
cap.
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor straight antifreeze. The correct mixture of water
and antifreeze must be used to provide proper lubrication, corrosion protection
and cooling. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.
Page 758 of 917
757
ES350_300h_OM_OM33A60U_(U)
7
When trouble arises
7-2. Steps to take in an emergency
If you think something is wrong
●Fluid leaks under the vehicle.
(Water dripping from the air conditioning after use is normal.)
●Flat-looking tires or uneven tire wear
●Engine coolant temperature gauge needle continually points higher
than normal.
●Changes in exhaust sound
●Excessive tire squeal when cornering
●Strange noises related to the suspension system
●Pinging or other noises related to the engine
●Engine missing, stumbling or running roughly
●Appreciable loss of power
●Vehicle pulls heavily to one side when braking
●Vehicle pulls heavily to one side when driving on a level road
●Loss of brake effectiveness, spongy feeling, pedal almost touches the
floor
If you notice any of the following symptoms, your vehicle probably
needs adjustment or repair. Contact your Lexus dealer as soon as pos-
sible.
Visible symptoms
Audible symptoms
Operational symptoms
Page 822 of 917
821
ES350_300h_OM_OM33A60U_(U)
7
When trouble arises
7-2. Steps to take in an emergency
If your vehicle overheats (gasoline vehicles)
Stop the vehicle in a safe place and turn off the air conditioning system,
and then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the engine has cooled down sufficiently, inspect the hoses and
radiator core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( P. 9 5 )
enters the red zone or a loss of engine power is experienced. (For
example, the vehicle speed does not increase.)
●Steam comes out from under the hood.
Correction procedures
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Page 823 of 917
8227-2. Steps to take in an emergency
ES350_300h_OM_OM33A60U_(U)
The coolant level is satisfactory if it is between the “FULL” and “LOW”
line on the reservoir.
Reservoir
“FULL”
“LOW”
Radiator cap
Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
Start the engine and turn the air conditioning system on to check that
the radiator cooling fa ns operate and to check for coolant leaks from
the radiator or hoses.
The fans operate when the air conditioning system is turned on immediately after
a cold start. Confirm that the fans are operating by checking the fan sound and air
flow. If it is difficult to check these, tu rn the air conditioning system on and off
repeatedly. (The fans may not operate in freezing temperatures.)
If the fans are not operating:
Stop the engine immediately and contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
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Page 824 of 917

8237-2. Steps to take in an emergency
ES350_300h_OM_OM33A60U_(U)
7
When trouble arises
CAUTION
■When inspecting under the hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns.
●If steam is seen coming from under the hood, do not open the hood until the
steam has subsided. The engine compartment may be very hot.
●Keep hands and clothing (especially a tie, a scarf or a muffler) away from the fans
and belts. Failure to do so may cause the hands or clothing to be caught, resulting
in serious injury.
●Do not loosen the radiator cap or the coolant reservoir cap while the engine and
radiator are hot. High temperatur e steam or coolant could spray out.
NOTICE
■When adding engine coolant
Add coolant slowly after the engine has cooled down sufficiently. Adding cool
coolant to a hot engine too quickly can cause damage to the engine.
■To prevent damage to the cooling system
Observe the following precautions:
●Avoid contaminating the coolant with foreign matter (such as sand or dust etc.).
●Do not use any coolant additives.
Page 825 of 917

824
ES350_300h_OM_OM33A60U_(U)
7-2. Steps to take in an emergency
If your vehicle overheats (hybrid vehicles)
■If the needle of the engine coolant temperature gauge enters the red
zone
Stop the vehicle in a safe place an d turn off the air conditioning sys-
tem, and then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the hybrid system has cooled down sufficiently, inspect the
hoses and cooling system for leaks.
Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact your
Lexus dealer.
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( P. 9 5 )
enters the red zone or a loss of hybrid system power is experienced.
(For example, the vehicle speed does not increase.)
●“Hybrid System Overheat” ( P. 780) is shown on the multi-informa-
tion display.
●Steam comes out from under the hood.
Correction procedures
1
2
3
1
2
Page 828 of 917

8277-2. Steps to take in an emergency
ES350_300h_OM_OM33A60U_(U)
7
When trouble arises
Start the hybrid system and check for the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the nearest Lexus dealer.
CAUTION
■When inspecting under the hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns.
●If steam is seen coming from under the hood, do not open the hood until the
steam has subsided. The engine compartment may be very hot.
●After the hybrid system has been turned off, check that the indicator on the
“POWER” switch and the “READY” indicator are off.
When the hybrid system is operating, the gasoline engine may automatically
start, or the cooling fan may suddenly oper ate even if the gasoline engine stops.
Do not touch or approach rotating parts such as the fan, which may lead to fin-
gers or clothing (especially a tie, a scarf or a muffler) getting caught, resulting in
serious injury.
●Do not loosen the radiator cap or the coolant reservoir cap while the hybrid sys-
tem and radiator are hot. High temper ature steam or coolant could spray out.
NOTICE
■When adding engine/power control unit coolant
Add coolant slowly after the hybrid syst em has cooled down sufficiently. Adding
cool coolant to a hot hybrid system too quickly can cause da mage to the hybrid
system.
■To prevent damage to the cooling system
Observe the following precautions:
●Avoid contaminating the coolant with foreign matter (such as sand or dust etc.).
●Do not use any coolant additives.
6